Many techniques have been developed for monitoring the course of a polymerization reaction. Infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) have been used to monitor the depletion of monomers and the subsequent production of the product polymers, but these techniques provide little information on the thermodynamics of the reactions studied, particularly the heat evolved. Calorimetry, and differential scanning calorimetry has been used to study the exotherms of polymerization reactions, but these techniques provide information only on the bulk sample per se; it is not possible to obtain information about the thermal characteristics, such as the exothermicity or heat evolution from areas, or regions of a particular sample.
Optical pyrometry has been used effectively for measuring the surface temperatures of various materials, particularly incandescent materials, and in evaluating catalytic activity, reactivity of monomers or other reactants, the rates of reactions, or reaction conditions of thin film samples. Typically a thin film sample is evaluated and the temperatures of the samples are recorded. Higher peak temperatures, for example, have been used to screen various catalysts, with those samples exhibiting higher peak temperatures presumed to have higher catalytic activity under a given set of conditions.